1. Technical Field
The present invention relates to a vehicular display apparatus that is mounted to a vehicle, and that displays a first image generated by a first drawing unit and a second image generated by a second drawing unit.
2. Description of Related Art
A known vehicular display apparatus divides a display screen of a display unit, which is installed so as to face an occupant of a vehicle, into multiple display areas, and displays multiple images on respective display areas of the display screen. For example, a display apparatus disclosed in Patent Document 1 (JP-A-H06-195056) displays multiple images side by side on a monitor. The multiple images are for example a navigation image generated by a navigation controller, a TV screen image generated by a TV tuner and a decoder, or the like.
In Patent Document 2 (JP-A-2010-108255), a navigation electronic control unit (ECU) connected to an in-vehicle manipulation system generates an image in which a navigation image and an audio image are placed side by side. The navigation image relates to a navigation function and the audio image is for control of an audio function. On the display screen of a display unit, a pointer is superimposed on the image generated by the navigation ECU. The in-vehicle manipulation system can receive an input of user request. The user request may include a movement request for moving the display position of the pointer on the display screen, a change request for changing a display manner of the display screen into another display manner, and the like. In the above, the another display manner may be associated with a specific display position of the pointer
In the above configuration, the navigation image and audio image are displayed side by side on the display screen of the display unit, and the pointer is superimposed on, for example, the navigation image out of the navigation image and audio image. In this state, when the movement request for moving the display position of the pointer into a display area of the audio image may be inputted to the in-vehicle manipulation system, the pointer becomes movable in the display area of the audio image. In addition, the display manner of the audio image become changeable in response to the change request inputted via an in-vehicle manipulation system.
In the configuration of Patent Document 2, the navigation image and the audio image are generated by the same drawing unit, which is the navigation ECU. Therefore; when the navigation ECU changes the display position of the pointer, the pointer on the display screen is freely movable from one display area for displaying the navigation image to another display area for displaying the audio image. Thus, the configuration disclosed in Patent Document 2 allows the display position of the pointer to move from one of the two display areas to the other of the two display areas with ease.
In recent years, the number of display pixels of a display unit has remarkably increased due to the trend toward a large-sized display unit and higher definition. Accordingly, a drawing unit should generate an image having the increased number of pixels in line with an increase in the number of display pixels of the display unit. However, from the viewpoint of the processing capacity of the drawing unit, it has become difficult for a single drawing unit to generate multiple images each having the increased number of pixels, and it has become difficult to display the multiple images side by side. It should be noted that, in Patent Document 2, multiple images to be displayed side by side are generated by a single drawing unit. Therefore, there is an increasing demand for a vehicular display apparatus that can displays, side by side, multiple images generated by different drawing units.
In this relation, when the navigation image and the TV screen image are generated by different drawing units (this is the case of Patent Document 1), operability may be degraded. Specifically, even when an input unit receives an input of the movement request for moving the display position of the pointer image from the display area of the navigation image into the display area of the TV screen image, the pointer image is not allowed to move into the display area of the TV screen image. Thus, the display manner of the TV screen image cannot be changed in response to the change request inputted via the input unit. As can be seen above, when a vehicular display apparatus is configured such that the multiple images to be displayed side by side are generated by different image units, operability may be degraded.